1. Field of the Invention
This invention relates to machines for cleaning, polishing and otherwise processing floors. More particularly, it concerns a floor machine having several advantageous structural features including an improved dead-man control switch, a simple effective handle-adjusting mechanism, an effective splash guard, a compact drive gear arrangement, and an effective cooling system.
2. Description of the Prior Art
It has been generally considered that for a floor machine of the type in which the full weight of the machine rests on the pad during operation to be effective for all desired operations, the machine had to weigh at least 100 pounds and the speed of its pad when in contact with the floor could not exceed approximately 350 rpm. These values were dictated in part by the fact that, for effective cleaning, a certain degree of downward pressure on the floor is necessary and to the fact that in certain operations, such as wet stripping, high speed of the pad was believed to cause hydroplaning of the pad with resulting ineffective floor contact. Accordingly, many present machines use rather heavy drive mechanisms designed to provide pad speeds below 350 rpm. On the other hand it has been recognized that pad speed greater than 350 rpm will result, in some instances in a superior finish on the floor. In one machine, speeds above 350 rpm are used but in this case part of the weight is supported on two rear wheels which remain in contact with the floor at all times and, as a result, the machine is moved in a more or less straight line forward and backward motion. Since a large portion of the weight of such machines is carried during operation by the wheels and, in one such machine, only about 13 to 15 pounds is effectively concentrated on the pad. In general, prior machines that have a weight of 100 pounds or more, rotate relatively slowly while in machines whose pads rotate at much higher speeds, the engagement of the wheels with the floor during operation restricts the weight of the machine from being applied fully to the pads.
Dead-man switch arrangements have been provided for floor machines which make use of various mechanisms, adapted to be associated with the cross-bar of the handle of the machine, including levers pivoted on fixed pins that are parallel to the cross-bar, levers pivoted on pins that are generally normal to the cross-bar, bars that are mounted for sliding movement toward and away from the cross-bar, and tubular members that are adapted to rotate on the cross-bar of the handle in the manner used in motorcycle hand controls. Apparatus has also been provided for permitting the handle to be moved to and to remain in any one of several pivoted angular positions between a vertical position and downwardly pivoted positions. Conventionally, to retain the handle in a selected angular position, some type of latch mechanism is used. When it is desired to move the handle to a different position, the operator must first release the latch. When the desired position is reached, the latch must be reengaged.
Several types of splash guards are currently being used on floor machines. In general, each of these consists of a splash ring that is adapted to lie loosely on the floor around the rotatable pad or brush in a position to be pushed by the machine as it moves over the floor.
In operation the control and manuevering of the machine is, of course, accomplished largely by the operator through his grip on the cross-bar of the handle. It is common practice to provide ridges, protuberances and grooves on the gripping areas in an attempt to assure maximum control. Other structural features of current floor machines, such as motor-driven gear drives, are in general of conventional design.